1. Field of the Invention
The present invention relates to technology for an air shower apparatus to be installed at an entrance or the like to a clean room at, for example, a semiconductor manufacturing plant.
2. Description of Related Art
Conventionally, an air shower apparatus is installed at an entrance to a clean room in order to maintain the clean atmosphere required for a clean room for manufacturing semiconductors and electronic parts, etc.
All people who enter the clean room enter an air shower chamber S in order to remove dust particles attached to clothing etc. Upon entering the chamber, a turbo fan operates and clean air is blown out of an air blower. The flow of clean air first passes through a pre-filter, is pressurized by the turbo fan, passes through a high-performance dust collecting filter and is then blown out from the air blower as a high-speed flow of clean air. The clean air that is blown out then removes the dust particles attached to a person's clothes etc. and is again sucked back into circulation at the pre-filter.
However, the following problems exist with related air shower apparatus.
Firstly, as the air blower is fixed, the clean air does not thoroughly collide with people's bodies and the efficiency with which dust particles are removed is poor.
Secondly, as the air is only blown out in a fixed direction towards the person, air including clean air blown out from the air blower and air with dust particles removed flows as convection currents within the air shower and dust particles therefore become re-attached to clothes etc.
Thirdly, there is also the fear that when high-speed air is being blown out from the air blower, as the air shower chamber is at positive pressure with respect to the atmosphere within the clean room, air contaminated with dust particles will leak into the clean room from gaps between a door, etc.